all: fix a number of misuses of the word "an"

After golang.org/cl/210124, I wondered if the same error had gone
unnoticed elsewhere. I quickly spotted another dozen mistakes after
reading through the output of:

	git grep '\<[Aa]n [bcdfgjklmnpqrtvwyz][a-z]'

Many results are false positives for acronyms like "an mtime", since
it's pronounced "an em-time". However, the total amount of output isn't
that large given how simple the grep pattern is.

Change-Id: Iaa2ca69e42f4587a9e3137d6c5ed758887906ca6
Reviewed-on: https://go-review.googlesource.com/c/go/+/210678Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Zach Jones <zachj1@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

doc/articles/go_command.html

@@ -74,7 +74,7 @@ important, the use of the tool itself.</p>
 <p>The <code>go</code> command requires that code adheres to a few key,
 well-established conventions.</p>
 
-<p>First, the import path is derived in an known way from the URL of the
+<p>First, the import path is derived in a known way from the URL of the
 source code.  For Bitbucket, GitHub, Google Code, and Launchpad, the
 root directory of the repository is identified by the repository's
 main URL, without the <code>http://</code> prefix.  Subdirectories are named by

src/archive/tar/reader.go

@@ -433,7 +433,7 @@ func (tr *Reader) readHeader() (*Header, *block, error) {
 			// files generated by a pre-Go1.8 toolchain. If the generated file
 			// happened to have a prefix field that parses as valid
 			// atime and ctime fields (e.g., when they are valid octal strings),
-			// then it is impossible to distinguish between an valid GNU file
+			// then it is impossible to distinguish between a valid GNU file
 			// and an invalid pre-Go1.8 file.
 			//
 			// See https://golang.org/issues/12594

src/cmd/link/internal/ld/deadcode.go

@@ -306,7 +306,7 @@ func (d *deadcodepass) init() {
 	}
 
 	for _, name := range names {
-		// Mark symbol as an data/ABI0 symbol.
+		// Mark symbol as a data/ABI0 symbol.
 		d.mark(d.ctxt.Syms.ROLookup(name, 0), nil)
 		// Also mark any Go functions (internal ABI).
 		d.mark(d.ctxt.Syms.ROLookup(name, sym.SymVerABIInternal), nil)

src/cmd/link/internal/ld/deadcode2.go

@@ -113,7 +113,7 @@ func (d *deadcodePass2) init() {
 	}
 
 	for _, name := range names {
-		// Mark symbol as an data/ABI0 symbol.
+		// Mark symbol as a data/ABI0 symbol.
 		d.mark(d.ldr.Lookup(name, 0), 0)
 		// Also mark any Go functions (internal ABI).
 		d.mark(d.ldr.Lookup(name, sym.SymVerABIInternal), 0)

src/cmd/pprof/readlineui.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// This file contains an driver.UI implementation
+// This file contains a driver.UI implementation
 // that provides the readline functionality if possible.
 
 // +build darwin dragonfly freebsd linux netbsd openbsd solaris windows

src/crypto/elliptic/p256.go

@@ -307,7 +307,7 @@ func p256Diff(out, in, in2 *[p256Limbs]uint32) {
 }
 
 // p256ReduceDegree sets out = tmp/R mod p where tmp contains 64-bit words with
-// the same 29,28,... bit positions as an field element.
+// the same 29,28,... bit positions as a field element.
 //
 // The values in field elements are in Montgomery form: x*R mod p where R =
 // 2**257. Since we just multiplied two Montgomery values together, the result

src/encoding/gob/gobencdec_test.go

@@ -707,7 +707,7 @@ func TestGobEncoderExtraIndirect(t *testing.T) {
 
 // Another bug: this caused a crash with the new Go1 Time type.
 // We throw in a gob-encoding array, to test another case of isZero,
-// and a struct containing an nil interface, to test a third.
+// and a struct containing a nil interface, to test a third.
 type isZeroBug struct {
 	T time.Time
 	S string

src/io/io_test.go

@@ -13,7 +13,7 @@ import (
 	"testing"
 )
 
-// An version of bytes.Buffer without ReadFrom and WriteTo
+// A version of bytes.Buffer without ReadFrom and WriteTo
 type Buffer struct {
 	bytes.Buffer
 	ReaderFrom // conflicts with and hides bytes.Buffer's ReaderFrom.

src/io/multi_test.go

@@ -286,7 +286,7 @@ func TestMultiReaderSingleByteWithEOF(t *testing.T) {
 	}
 }
 
-// Test that a reader returning (n, EOF) at the end of an MultiReader
+// Test that a reader returning (n, EOF) at the end of a MultiReader
 // chain continues to return EOF on its final read, rather than
 // yielding a (0, EOF).
 func TestMultiReaderFinalEOF(t *testing.T) {

src/reflect/type.go

@@ -646,7 +646,7 @@ func resolveNameOff(ptrInModule unsafe.Pointer, off int32) unsafe.Pointer
 // Implemented in the runtime package.
 func resolveTypeOff(rtype unsafe.Pointer, off int32) unsafe.Pointer
 
-// resolveTextOff resolves an function pointer offset from a base type.
+// resolveTextOff resolves a function pointer offset from a base type.
 // The (*rtype).textOff method is a convenience wrapper for this function.
 // Implemented in the runtime package.
 func resolveTextOff(rtype unsafe.Pointer, off int32) unsafe.Pointer

src/runtime/alg.go

@@ -344,7 +344,7 @@ func initAlgAES() {
 	getRandomData(aeskeysched[:])
 }
 
-// Note: These routines perform the read with an native endianness.
+// Note: These routines perform the read with a native endianness.
 func readUnaligned32(p unsafe.Pointer) uint32 {
 	q := (*[4]byte)(p)
 	if sys.BigEndian {

src/runtime/runtime1.go

@@ -486,7 +486,7 @@ func reflect_resolveTypeOff(rtype unsafe.Pointer, off int32) unsafe.Pointer {
 	return unsafe.Pointer((*_type)(rtype).typeOff(typeOff(off)))
 }
 
-// reflect_resolveTextOff resolves an function pointer offset from a base type.
+// reflect_resolveTextOff resolves a function pointer offset from a base type.
 //go:linkname reflect_resolveTextOff reflect.resolveTextOff
 func reflect_resolveTextOff(rtype unsafe.Pointer, off int32) unsafe.Pointer {
 	return (*_type)(rtype).textOff(textOff(off))